Mobile telephone subscribers are typically charged a flag fall per call as well as a usage fee based on the duration of the call. This timed rate is typically higher than the corresponding rate for users of fixed line networks. In some markets, fixed line callers are charged a fixed fee per call, with no time based fee. As a consequence, mobile subscribers, when at home, frequently use their fixed line service in preference to their mobile phone.
Mobile operators are seeking ways to increase the usage of their networks. One method is to encourage mobile users to continue to use their mobiles even when at home, in preference to fixed line services. To achieve this, mobile operators must lower their charges to be comparable with the fixed line charges.
This is sometimes referred to as zone based charging. The mobile subscriber is charged a normal mobile rate while away from home, but a lower rate whilst at home.
In order for this to work effectively, the mobile network must be able to distinguish between when the mobile caller is at home and away from home.
It is therefore an object of the present invention to provide a method and/or system for determining whether a particular mobile is in or out of a particular zone.